Extra patterns, boundaries, cases, and utilities on top of convert_case.

• is_case(s, case): checks if a string matches a specified case
• CaseDetector: a builder-pattern struct for detecting which cases a string matches
  • CaseDetector::new(): creates an empty detector
  • CaseDetector::default(): creates a detector with all standard cases
  • .add_case() / .add_cases(): add cases to the detection pool
  • .remove_case() / .remove_cases(): remove cases from the pool
  • .detect_cases(s): returns all cases from the pool that match the string

• case::TOGGLE: words start with lower case and remainder are upper case
• case::ALTERNATING: words alternate between upper and lower case
• random feature:
  • case::RANDOM: letters are randomly lower case or upper case
  • case::PSEUDO_RANDOM: pairs of letters are randomly lower-upper, or upper-lower